Very popular beverages today are those commonly referred to as "frozen" drinks whereby a portion of liquid, which often includes liquor, and a portion of ice are mixed in a blender to create an almost slush-like drink. In the past, the most typical manner to create such drinks required the bartender or other operator to put a quantity of liquor, flavored drink mix, ice and possibly even fruit in the pitcher of a blender, and then operate the blender until that drink is perceived to be adequately mixed. The drink is then transferred from the pitcher of the blender to a glass for consumption by the patron.
Such a procedure has many disadvantages. For example, this procedure requires the constant attention of the operator who, in the sometimes busy environment of a restaurant or cocktail lounge, could be giving his attention to making other drinks while the frozen drink is being prepared. Moreover, even the skilled bartender cannot, in this manner, always make drinks which are consistent in quantity and quality. That is, the operator is required to guess to the correct amount of liquid and ice to put into the blender, dependent on the number of drinks to be made, and if insufficient ingredients are blended, the patron's glass will not be filled on the first try, and the operator will be required to blend additional liquid and ice. Or, as often is the case, the operator may blend too large a quantity of ingredients which, if not eventually used, is wasteful to the economic detriment of the establishment. Moreover, there is no way to assure that the quality of the drink is consistent from drink-to-drink. If patrons have enjoyed a good first drink, they expect that their second drink will be of the same consistency and flavor of their first drink, which cannot always happen when the operator is required to "eyeball" the amount of liquid relative to the amount of ice to be blended.
One proposed solution to at least some of the aforementioned problems is to provide a combined ice dispenser and blender whereby the functions of each are controlled by time. Such is shown, for example, in U.S. Patent No. 4,528,824 and 4,681,030. In these devices, an attempt is made to control the amount of ice to be delivered to the blending cup by operating an ice shaver for a predetermined amount of time. Then, after a predetermined time delay, the blender operates for a preselected amount of time. However, repeatably consistent drinks cannot be made by such a device in that there is no correlation between the amount of liquid which is manually placed in the cup of the blender and the amount of ice to be delivered. Moreover, using time as the operative control parameter does not assure that the correct or precise quantity of ice has been added. For example, the ice machine might be almost empty, thereby not having a sufficient quantity of ice for the drink, yet this prior art device would run for a predetermined time and deliver an incorrect quantity of ice. Or, even if there was sufficient ice in the machine, it will not always be delivered at a uniform rate and might not even be delivered at all, as could happen if the ice delivering blades were operating in a dead air space created by an arching of the ice in the machine.
Thus, controlling the operation of a drink-making machine using time as the controlling parameter does not adequately solve the problems prevalent in the art.